1. Field of the Invention
The present invention relates to an image processing apparatus and system and, more particularly, to an image processing apparatus and system, which can transfer an image to be formed to an image forming apparatus via a digital interface.
2. Related Background Art
In recent years, higher-speed digital interfaces have been developed, and for example, a universal serial bus (USB) and faster IEEE1394-1995 (High Performance serial bus) (to be referred to as a 1394 serial bus hereinafter) are known.
Such serial buses have been developed to transfer a large volume of data such as audio data, video data, and the like in real time among a home digital VTR, electronic camera, and PC (personal computer).
On the other hand, as color scanners, color copying machines, color printers, and the like have gained higher performance, these apparatuses are often connected to the PC. Hence, if these apparatuses are connected to the PC via the 1394 serial bus, a color image can be printed out, e.g., a color image captured using a video camera can be printed out via the 1394 serial bus.
The 1394 serial bus has an asynchronous transfer mode (asynchronous transfer) and synchronous transfer mode (isochronous transfer). More specifically, asynchronous transfer is a one-to-one transfer mode for transmitting data from a source node to a destination node during an idle time of isochronous transfer (to be described below, and is used for transferring data with a small information volume, e.g., text data, commands, still image data, and the like.
On the other hand, isochronous transfer is a characteristic mode of the 1394 serial bus, and is especially suitable for transferring data that requires real-time transfer such as video data, audio data, and the like. Also, asynchronous transfer is a one-to-one transfer mode, but isochronous transfer can transfer data from one node to all other nodes by a broadcast function. These two modes can use a bus time-divisionally, and the 1394 serial bus is characterized by having these two modes.
However, asynchronous transfer alone may not fully use the functions of a printer since recent printers have multiple functions and higher resolutions. More specifically, when the printer for printing out an image is designated and high-resolution color images are successively printed out in the asynchronous transfer mode, the transfer time may become larger than the time required for printouts.
Also, asynchronous transfer designates a specific node connected to the 1394 serial bus. For this reason, even when a plurality of printers are connected to the 1394 serial bus, if a plurality of identical color images are to be printed out, the transfer time is likely to be much larger than the time required for printouts.
If printouts are always executed in the isochronous transfer mode, the print data requires a considerably large band occupation time of the 1394 serial bus, and disturbs transfer of real-time data among apparatuses such as a video camera that requires temporary continuous data transfer.
It is an object of the present invention to solve the above-mentioned problems.
It is another object of the present invention to provide an image processing apparatus and system, which can effectively use the functions of an interface, and can fully use the functions of an image forming apparatus.
In order to achieve the above objects, according to one aspect of the present invention, an image processing apparatus connected to a plurality of image forming apparatuses via an interface, comprises image output means for transmitting an image to be formed via the interface, input means for inputting an image forming condition, and mode designation means for designating an image communication mode in the interface in accordance with the image forming condition input by the input means.
With this arrangement, the performance of the plurality of image forming apparatuses can be effectively used without lowering the performance of the interface itself.
According to another aspect of the present invention, an image processing apparatus connected to an image forming apparatus via an interface, which has at least a synchronous mode for transferring a predetermined volume of data at predetermined periods, and an asynchronous mode for transferring data in an idle time of data transmission in the synchronous mode, comprises image output means for transmitting an image to be formed via the interface, input means for inputting an image forming condition, and mode designation means for selecting one of the synchronous and asynchronous modes of the interface in accordance with the image forming condition input by the input means.
According to the image processing apparatus with the above arrangement, since the synchronous and asynchronous modes can be appropriately selectively used, the performance of the image forming apparatus and, hence, the functions of the interface can be effectively used.